A research group composed of RIVM, Alterra, Deltares, IRAS and RWS has selected several methods that can improve the accuracy when used to perform risk assessments of contaminated soils. These methods can be employed to determine which fraction of the contaminants present in the soil is actually biologically available and forms a risk to plants and animals living in the soil. Scientific studies have proven that only the bioavailable fraction of the contaminant is able to exert negative effects on the soil ecosystem. Not all of the contaminants, both in terms of quantity and species, are taken up by plants or animals. The proposed methods can supplement the current approach used to perform risk assessments of soil ecosystems in the Netherlands
Abstract Environmental risk assessment of chemicals is mostly based on the results of standardized toxicity tests. To obtain environmental quality criteria, extrapolation factors are used that depend on the amount and quality of available data. These extrapolation factors do not, however, take into account the mode of action of the compound tested or the life history of the test organism. In this study, we analyzed the variability in acute‐to‐chronic ratios (ACRs) for various chemicals in relation to their mode of action. Chemicals were classified as nonpolar narcotics, polar narcotics, specifically acting compounds, and heavy metals. As an acute endpoint, the LC50 was used; as a chronic endpoint, the lowest test concentration at which the natural rate of population increase ( r ) is affected, or LOEC( r ), was used. Data were derived from the on‐line literature. Nonpolar narcotic chemicals demonstrate the smallest variation in ACRs, and acute tests can be used to derive chronic endpoints for this class. For the other classes, the variation in ACRs is larger. Fish species especially show a relatively large ACR. For heavy metals, differences in the mode of action may play an important role in explaining differences in ACRs. For the other three classes, however, it is less reliable to predict chronic toxicity using the results of acute tests. In general, differences in species sensitivity rather than in mode of action for the chemical seem to determine differences in ACRs.
In het project Ketenverkenner van de Kennisimpuls Waterkwaliteit wordt voor drie stofgroepen in kaart gebracht hoe ze de waterkwaliteit beinvloeden. Beschikbare kennis wordt verzameld, vragen van waterbeheerders worden opgehaald en relevante kennisleemtes worden geidentificeerd en waar mogelijk ingevuld. Waar nodig worden mogelijke maatregelen die emissies naar het watermilieu kunnen verminderen geinventariseerd. De beschikbare kennis blijkt verspreid aanwezig, wat het samenbrengen ervan voor gebruik door waterbeheerders zinvol maakt. Dit toont dat het nog grotendeels onbekend is in welke mate deze stofgroepen de waterkwaliteit beinvloeden. De beschikbare gegevens worden gebruikt om verdere onderzoeksvragen te prioriteren.
de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.
Veterinary pharmaceuticals (VPs) are emitted into the environment and transfer to groundwater and surface water is diffuse and complex, whereas actual information on the fate is frequently limited. For 17 VPs of potential concern in the Netherlands, we assessed sources and emission due to animal slurry applications to soil. Hence, we examined the use of VPs in four livestock sectors in the Netherlands for 2015-2018, and quantified animal excretion rates and dissipation during slurry storage. For almost all VPs, administrated quantities to the animals during the period 2015-2018 decreased. VP concentrations during a storage period of six months could decrease between 10 and 98% depending on the compound. Predicted concentrations of VPs in slurries after storage compared well with measured concentrations in the literature. Based on the storage model outcomes, we developed a residue indicator, that quantifies the potential for residues in applied slurry. This indicator agrees well with the most frequently detected VPs in the Dutch slurries, and is therefore useful to prioritize measures aiming at reducing VP emissions into the environment.
The aim of the present study was to assess whether population effects and recovery times increase when a population of a vulnerable aquatic invertebrate is exposed to concentrations of 1 or multiple pesticides. The 2 sets of pesticide combinations tested are typical for orchard and tuber crops in The Netherlands. Exposure concentrations were predicted using the FOCUS step 3 modeling framework and the Dutch drainage ditch scenario. Recovery times were assessed using the MASTEP population model. We simulated the population dynamics and pesticide effects in a Monte Carlo style by using median effective concentration values drawn from an arthropod species sensitivity distribution. In the tuber scenario, exposure to λ-cyhalothrin resulted in long-term effects, whereas exposure to the co-occurring compound fluazinam hardly resulted in (additional) effects. In the orchard scenario, 3 pesticides resulted in large effects just after exposure, but pulse exposures to these compounds did not coincide. The probabilities of effects for the single compounds added up for the combination; in contrast, the recovery times were not higher for the combination compared to those associated with exposure to the individual compounds. The conclusion from the present study's simulations is that exposure to the evaluated pesticide packages may lead to increased mortality probabilities and effect sizes of the combination, but does not lead to longer recovery times for populations with synchronized reproduction than when exposed to the individual compounds.
